1. Field of the Invention
This invention relates to the field of cables. More specifically, the invention comprises a system for attaching conventional bolts or threaded rods to an end of a cable.
2. Description of the Related Art
Devices for mounting a termination on the end of a wire, rope, or cable are disclosed in U.S. Pat. No. 7,237,336, which is incorporated herein by reference.
The individual components of a cable are known by various terms, such as “fibers,” “wires,” or “strands.” The nomenclature used often depends on the material used—such as steel “wire,” hemp “fibers,” or Kevlar “strands.” This invention disclosed herein can be applied to virtually any type of cable assembly, though its main application is for use with synthetic cables. For purposes of uniformity, the individual components of the cables described will be referred to as “strands” throughout this application.
Some type of fitting must typically be added to a cable in order to transmit a load to the cable. One of the most common methods of attaching a fitting is by potting. FIG. 1 shows anchor 18 attached to an end of cable 10 (Only a small length of the cable is shown, though it is typically much longer). FIG. 2 shows the same combination sectioned in half to show internal features. Anchor 18 can be attached to the strands of the synthetic cable by a variety of techniques. The version shown is attached by potting a length of strands into an expanding central cavity through the anchor.
The term “potting”—which is well known to those skilled in the art—can be described as follows: The cable strands are typically splayed into a diverging pattern and infused with liquid potting compound (using a variety of known techniques). The liquid potting compound is any substance which transitions from a liquid to a solid over time. The most common example would be a cross-linking adhesive such as an epoxy. Those skilled in the art know that such adhesives use two separate liquids which cross-link when mixed together. Such a liquid is mixed just prior to wetting the strands.
The wetted strands are at some point placed in tapered cavity 34 within anchor 18 (in some cases prior to wetting and in some cases after wetting), so that when the liquid potting compound hardens the strands will be locked to the anchor. The anchor and the portion of cable locked therein are then collectively referred to as a termination.
Potted region 44 consists of strands locked within the solidified potting compound. The anchor is thereby attached to the cable. The anchor has a first end which is approximately even with the end of the cable and a second end proximate to the cable but distal to the end of the cable (the lower end in the orientation shown in the view).
The termination of FIG. 2 is an effective attachment of an anchor to a synthetic cable. Other attachment methods are well known, including “spike and cone” fittings, compression fittings, knot anchorages, and splice anchorages. The present invention could be used with any of these prior art techniques. Because potting is the most common, it is the attachment method shown in most of the drawings. The actual invention is not dependent upon how the anchor is attached to the cable, however. Thus, most of the methods for creating such an attachment are not shown.
It is often desirable for a cable termination to include a long threaded rod. If such a rod is locked into another fitting, then a nut placed on the threaded rod can be used to draw the cable taut and apply a controlled amount of tension. However, as most anchors are made by machining, incorporating a threaded rod requires substantial material removal and finishing operations. On the other hand, separate standard threaded rods and bolts are quite cheap. If one can provide an anchor which can capture a conventional threaded rod or bolt in order to include a threaded attachment, substantial savings will result.